A Ca2+ sensor-transcription factor cascade regulates cell-wall fortification and broad-spectrum disease resistance in rice.

Abstract

Crop production is persistently threatened by a multitude of destructive diseases. In rice, the Ca2+ sensor RESISTANCE OF RICE TO DISEASES1 (ROD1) is a key regulator of defense against major pathogens, including those causing blast, sheath blight, and bacterial blight. However, the molecular mechanisms underlying ROD1-mediated immune suppression remain largely elusive. Here, we characterize an immune signaling cascade comprising the B3-domain transcription factor OsVAL2, the DOF transcription factor OsDOF3, as well as their downstream target OsCSE encoding a caffeoyl shikimate esterase. We demonstrate that the OsVAL2-OsDOF3-OsCSE module promotes lignin deposition and cell-wall fortification to confer broad-spectrum disease resistance. ROD1 interacts with and sequesters OsVAL2 in the cytoplasm, thereby preventing its nuclear accumulation and subsequent initiation of this immune program. Our findings reveal a spatiotemporal regulatory mechanism that maintains immune homeostasis, highlighting the crucial role of cell-wall remodeling in crop disease resistance.